Conventionally, electric power supply control circuits are provided. The circuit has: a electrifying line to be connected between a power source and a load; and a high-power semiconductor switching device, such as a power MOSFET, provided along the electrifying line. The circuit is configured to turn on/off the semiconductor switching device so as to control current supply to the load. One of such an electric power supply control circuit is configured to, when overcurrent passes, control electric potential at a control terminal of the semiconductor switching device so as to turnoff the semiconductor switching device, thereby shutting off power-supply. In other words, the semiconductor switching device is used also as a semiconductor fuse that protects the electrifying line (the wire) then.    [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2001-217696